1. Field of the Invention
This invention relates generally to equipment associated with operation of mines and quarries and, more particularly, to a hydraulic drilling machine.
2. Description of the Related Art
There is known a hydraulic drilling machine (cf., SU, A, 1,073,450) comprising a drill tool, a hydraulic motor for rotating the drill tool connected thereto through a reduction gear and having hydraulic pressure and discharge lines, and a hydraulic percussive mechanism having pressure and discharge lines communicating therewith via a rotatable fluid distributor, and a drive for rotating the fluid distributor. The hydraulic motor is used as a drive for rotating the fluid distributor in this hydraulic drilling machine. A separate hydraulic pressure line is used to feed the hydraulic motor rotating the fluid distributor.
In order to smoothly control the frequency and power of percussive action, use is made of a slide valve connected to the pressure lines of the hydraulic percussive mechanism and to the hydraulic motor rotating the drill tool.
The use of a hydraulic motor as the drive for rotating the fluid distributor necessitates extra consumption of liquid under pressure, and, accordingly, requires an additional pump.
As the slide valve is connected to the pressure lines the hydraulic motor rotating the drill tool and to hydraulic percussive mechanism, controlling the slide valve likewise necessitates more liquid under high pressure.
In addition, the above facilities fail to control the frequency and power of impacts delivered by the hammer of the percussive mechanism when reversing the hydraulic motor rotating the drill tool.
The aforedescribed overcomplicates the drilling machine in terms of its construction and control, as well as affects its reliability and reduces its operation efficiency.